VOGONS


First post, by Match451

User metadata
Rank Newbie
Rank
Newbie

Hello guys,

I have an old STB Voodoo2 with 1MB 90mhz RAM chips on it. It gets visual artifacts if it's overclocked to even 91mhz. I wanted to replace the ram to see if that fixes that problem, so I bought some 100mhz 512k chips off of ebay. Could anyone tell me if I can simply desolder the 1mb chips on the front of the card and add the 512k chips to all off the pads on the front and back of the card? Or will I need to change some resistors or something?

If someone knows of 1mb chips I could buy, I think I'd prefer that. I really don't know much about sourcing chips. I'd be especially curious if I could find some 110mhz or 125mhz, but I'm guessing those are impossible to find.

Thanks!

Reply 1 of 10, by Geri

User metadata
Rank Member
Rank
Member

I dont understand what you try to achieve by this. Ruining and randomly soldering around on a fully working card just to get one extra fps in some games (and lose third the performance in some others).

Regardless, all i know is 6 MB voodoo2 is possible, it existed as a prototype, but not as a retail product, as the manufacturers decided not to release it ever, because its stupid.

TitaniumGL the OpenGL to D3D wrapper:
http://users.atw.hu/titaniumgl/index.html

Reply 2 of 10, by Match451

User metadata
Rank Newbie
Rank
Newbie

There are 12 1MB chips on the card. I'm intending to replace them with 24 512k chips, not half the memory. There are 12 unpopulated pads on the back of the card I'd be filling. I just need to know if I need to change anything to configure it for 24 chips vs 12.

Reply 3 of 10, by Postman5

User metadata
Rank Newbie
Rank
Newbie

Most Voodoo2 work stably up to 98 MHz. What do the artifacts look like, are they from FBI or TMU? If from a FBI, then these are stripes or clear dots.
It's convenient to see this on the 3dfx Demo "Donut"

You can try everything step by step - remove 4 chips of 1 MB in TMU0, and put 4 chips of 512 instead. Mojo should say 2 MB on TMU0.
then solder 4 chips of 512k on the back side of the board. Mojo should say 4 MB on TMU0.

When increasing the memory from 8 to 12, no modifications or additions of resistors are required

Last edited by Postman5 on 2024-09-10, 09:25. Edited 2 times in total.

Reply 4 of 10, by paradigital

User metadata
Rank Oldbie
Rank
Oldbie
Match451 wrote on 2024-09-09, 23:23:

There are 12 1MB chips on the card. I'm intending to replace them with 24 512k chips, not half the memory. There are 12 unpopulated pads on the back of the card I'd be filling. I just need to know if I need to change anything to configure it for 24 chips vs 12.

12 unpopulated pads? Shouldn’t there be 8?

Both 8MB and 12MB cards use 512KB chips as it is.

Reply 7 of 10, by NostalgicAslinger

User metadata
Rank Member
Rank
Member
Postman5 wrote on 2024-09-10, 08:59:

Most Voodoo2 work stably up to 98 MHz.

Most Voodoo2 cards out there, also all my Voodoo2 cards from different brands, are using 100 MHz EDO RAM (25ns) chips, some rare ones have 110MHz (22ns) EDO chips . So 98MHz is not really a problem with 100MHZ EDO RAM, but the Voodoo2 from the Threadstarter only has 90MHz EDO RAM chips with 27ns). 91MHz is overclocking for this 27ns memory chips, and unfortunately one of the memory chips is a Monday model...

I also have a STB V2 1000 PCI 12MB, single sided and with 100MHz EDO memory.

Reply 8 of 10, by Postman5

User metadata
Rank Newbie
Rank
Newbie

Yes, i think you can replace 1MB chips with 512k and not change anything else on the board
Before doing this, make sure that on BlackMagic STB:
*****TMU0 (U13)
if memory chips 512k
pin 129 TMU0 (U13) > pin 14 U18; U17; U16; U12
pin 130 TMU0 (U13) > pin 14 U503; U502; U501; U506

if memory chips 1MB
pin 129 TMU0 (U13) > pin 14 U18; U17; U16; U12
pin 130 TMU0 (U13) > pin 15 U18; U17; U16; U12

***** for TMU1 (U3) the same pattern

*****FBI (U11)
if memory chips 512k
pin 126 FBI (U11) > pin 14 U14; U15
pin 127 FBI (U11) > pin 14 U507; U508
pin 124 FBI (U11) > pin 14 U19; U20
pin 125 FBI (U11) > pin 14 U504; U505

if memory chips 1MB
pin 126 FBI (U11) > pin 14 U14; U15
pin 127 FBI (U11) > pin 15 U14; U15
pin 124 FBI (U11) > pin 14 U19; U20
pin 125 FBI (U11) > pin 15 U19; U20

Reply 9 of 10, by Match451

User metadata
Rank Newbie
Rank
Newbie

Thanks for the responses, guys. I've attached some pictures of the card in question. And one of the new RAM chips, which are identified as "EliteMT 100mhz M11B416256A - 25J TZM1C806R 0818"

I'm noticing that on the front of the card, next to each of the populated 1MB RAM chips, are 3 tiny surface mount capacitors, but these are not populated on the back side of the card. Would I need to identify, source, and install those?

@Postman5, I must also admit I think tracing pins from the TMUs to RAM chips is a bit beyond my ability.

Attachments

  • V2 1000 Front.jpg
    Filename
    V2 1000 Front.jpg
    File size
    1.74 MiB
    Views
    334 views
    File license
    Public domain
  • V2 1000 Back.jpg
    Filename
    V2 1000 Back.jpg
    File size
    1.7 MiB
    Views
    334 views
    File license
    Public domain
  • Unpopulated.jpg
    Filename
    Unpopulated.jpg
    File size
    1.31 MiB
    Views
    334 views
    File license
    Public domain
  • New chip.jpg
    Filename
    New chip.jpg
    File size
    1.27 MiB
    Views
    334 views
    File license
    Public domain

Reply 10 of 10, by Postman5

User metadata
Rank Newbie
Rank
Newbie
Match451 wrote on 2024-09-13, 23:20:

are 3 tiny surface mount capacitors, but these are not populated on the back side of the card. Would I need to identify, source, and install those?

These are traditional blocking capacitors in power supply circuits. According to ancient legends, their values ​​should be different to reduce the effect of resonance. Usually there are combinations of 100pF, 1nF, 10nF, 100nF. The board can be turned on without them, but they are needed for stable operation and suppression of interference in power supply circuits.